The application relates to a belt roller for a safety belt.
A belt roller is known from the German Offenlegungsschrift DE 10 2009 032 101 A1. This previously known belt roller has a belt coil for winding and unwinding a safety belt, a lockable locking base which is connected to the belt coil and which is suitable for blocking the belt coil in the event of a rotation of the belt coil in the belt unwinding direction, and a force transmission element. The force transmission element couples the belt coil and the locking base in a locking position and is inactive in an unlocking position. Switching the force transmission element into an inactive state or moving the force transmission element from the locking position into the unlocking position is carried out with the previously known belt roller by means of a semi-annular inertia element which has two recesses of different depths and which allows the force transmission element to protrude to a greater or lesser extent from the belt coil depending on its position and consequently permits or prevents engagement in a recess of the locking base. The switching or the rotation of the semi-annular inertia element is carried out in a manner dependent on inertia as soon as a tightening drive of the belt roller is activated and a relative rotation of the belt coil relative to the inertia element is brought about.
There are further known from the prior art belt rollers in which shearable shearing pins connect the belt coil and the locking base to each other. If the force acting on the shearing pin exceeds a predetermined force threshold, the shearing pin is sheared off.